There are many situations in which it is beneficial, and in some cases necessary to have two materials used during an activity, where one of the materials is needed in less volume than the other. Some examples of such situations are: a fabric softener with a laundry detergent, a primer with a paint, a thinning agent with a concentrated chemical, a solidifier with an epoxy resin. In each of these cases, two containers are needed to store and carry the two combinable substances.
While separate containers are a fine method for storing the materials, the use of two containers has downside. For example it typically necessitates that the two products are somehow associated with one another so that the purchaser correctly buys the two proper components. It also requires additional shelf space in stores, which is becoming more and more difficult with the proliferation of various products for sale. There is also the problem that the products can become separated (either in the store or on the consumer's storage shelf) thus leading to wasted time searching for the product. Furthermore, manufacturers also risk loss of sales of one of the products if the consumer does not purchase the complimentary products together.
The primary solution to this issue has been to secure the secondary container to the primary container, such as packaging the two containers together (e.g., co-packaging the containers or shrink-wrapping the containers together), attaching the secondary container to the neck or handle of the primary container, such as with a plastic tie or ring, or adhering the secondary container to the side of the primary container. While these solutions address many of the problems associated with keeping two containers together during display in a store, they do not address the problem of keeping the containers together after purchase.
A need therefore exists for an improved container assembly for attaching two containers together where one is removably reattachable to the other.